I really wanted to know how these work. Great video.

*promote ingenious engineering

Promoting this video and sending it back into the queue for one more try; last queued Saturday, July 16th, 2016 5:07am PDT - promote requested by artician.

Is there an advantage to this design over a normal fan?

Yes (edit: Maybe?), some advantage. It utilises the venturi effect to increase the airflow beyond what you'd get from the tiny little fan in the bottom.

Many people think it's not a big enough advantage to pay the premium that commercial fans of this type tend to charge

Efficiency and you can stick your hand in it without hurting yourself.

But it's ridiculously expensive.

I would also guess that the power doesn't ramp up like a good box fan, either.

Eh, I'm not sure about that. Actual airflow is the same as whatever the small fan can move. The Venturi effect would just make the higher velocity airflow through the small fan channel into a lower velocity flow through the larger (main part) channel (it's basically a complicated diffusor). The actual rate of flow is the same. You probably actually lose a fair amount of efficiency because of all the ducting and diversion. I would also guess that small, high-speed fans aren't as efficient as larger low speed fans for the same airflow.

That isn't to say it isn't a cool design, though. But yeah, for just getting the job done, a box fan is probably more efficient and effective.

Hmm... you make a compelling argument Maybe I just got sucked into the marketing! Matthias's explanation even points out that venturi pumps are inefficient, and used where you don't want the liquid you're pumping anywhere near the inside of your pump.

The big disadvantage of using a small fan is normally that you get more noise, which I suppose might be overcome by the ducting.

I don't see any reason you couldn't use a larger fan in the setup though... you should even be able to use a box fan.

You don't need to buy an ultra expensive one, just don't buy anything from Dyson if you can avoid it. Amazon shows them starting at $13, I imagine there might be some model reasonably priced and decent quality.

http://www.telegraph.co.uk/technology/news/6377644/Dyson-fan-was-it-invented-30-years-ago.html

Dyson equipment sells for hundreds of dollars and has the build quality of about $10 per unit. I heard he only has to sell 1,000 units of an item to break even. It truly is ridiculous.

It's like when you "purchase" a condominium. You don't actually own what's behind the wall surfaces, so you just technically spent hundreds of thousands of dollars for airspace a few feet above ground. It only has value because other people pay for it too.